Carcass wrote:
Attachment:
GRE In triangle ABC, if AB = 4, then AC =.jpg
In triangle ABC, if AB = 4, then AC =
A 6
B 7
C 8
D 9
E 10
Since angles on a line must add to 180°, we can conclude that angle BCA = 30°, which means angle ABC = 90° (since all three angles in a triangle must add to 180°)
Notice that we have a special 30-60-90 right triangle.
Now let's add the information that tells us AB = 4
Notice that side AC is the hypotenuse, and side AB is the side opposite the 30° angle.
Let's add the base
30-60-90 special right triangle for reference.
Since the hypotenuse is always TWICE the length of the side opposite the 30° angle, we can conclude that AC = 2(4) = 8
Answer: C